Implement Deck Sharing Feature

Enable users to share their decks with other users via a shareable link or code. This includes creating a mechanism for exporting and importing deck data and handling potential conflicts or duplicates.

Priority Score

Quick estimate for initial prioritization

1.2B-Tier

Effort

5/10

Time Estimate

2-3 weeks

Decomposition of Feature Components

The 'Deck Sharing' feature can be broken down into several key technical components:

Backend/API:
- Generating unique shareable links/codes.
- Storing sharing permissions and associated deck IDs.
- API endpoints for creating, retrieving, and potentially revoking shares.
- Handling import logic: parsing shared data, merging/conflicting with existing decks.
- User authentication/authorization for sharing and importing.
Database:
- New tables to store shareable link data (e.g., share_id, deck_id, user_id, created_at, expires_at, access_level).
- Potentially modifying existing decks table to include sharing status.
Frontend:
- UI elements to trigger sharing (e.g., 'Share' button).
- Displaying the generated shareable link/code.
- UI for importing/accepting a shared deck (e.g., input field for code, confirmation dialog).
- Handling import success/failure feedback.
Export/Import Logic:
- Defining a standard format for deck data export (e.g., JSON).
- Implementing robust parsing and validation for imported data.
- Logic for merging or handling duplicate cards/decks upon import.

Estimation of Backend and Database Work

Estimating the backend and database effort:

Database Schema Design & Migration: Designing the new shares table and potentially altering existing ones. Creating and applying migration scripts. Estimate: 8 hours.
API Endpoint Development: Implementing endpoints for:
- Generating a share link (POST /decks/{id}/share): 4 hours.
- Retrieving share details (GET /shares/{code}): 3 hours.
- Importing a deck from a share (POST /decks/import): This involves parsing, validation, and potentially merging logic, which is more complex. Estimate: 12 hours.
- Revoking a share (DELETE /shares/{code}): 2 hours.
Business Logic for Sharing/Importing: Handling edge cases, user permissions, preventing infinite loops, dealing with large deck imports. Estimate: 10 hours.

Total Backend & Database: 8 + 4 + 3 + 12 + 2 + 10 = 39 hours.

Estimation of Frontend Work

Estimating the frontend effort:

Sharing UI: Button to initiate sharing, modal/dialog to display the link/code, copy-to-clipboard functionality. Estimate: 6 hours.
Import UI: Input field for share code, button to initiate import, confirmation modal for merge/overwrite choices, loading/success/error states. Estimate: 10 hours.
State Management: Integrating sharing and import flows into the existing application state. Estimate: 4 hours.
Displaying Shared Decks: Potentially a new section or indicator for decks imported via sharing. Estimate: 3 hours.

Total Frontend: 6 + 10 + 4 + 3 = 23 hours.

Estimation of Export/Import Logic & Testing

Estimating the core logic and quality assurance:

Data Export Format Definition: Choosing a format (e.g., JSON) and defining the schema for exported decks. Estimate: 3 hours.
Data Import Parsing & Validation: Implementing robust parsing of the chosen format, handling malformed data, validating against expected structures. This is critical for preventing data corruption. Estimate: 8 hours.
Conflict Resolution Logic: Defining rules for how to handle duplicate cards or decks during import (e.g., prompt user, auto-merge, skip). Estimate: 5 hours.
Unit Testing: Writing unit tests for API endpoints, business logic, and critical frontend components. Estimate: 10 hours.
Integration Testing: Testing the end-to-end flow of sharing and importing. Estimate: 8 hours.
QA & Bug Fixing: Manual testing, regression testing, and addressing bugs found during development and QA. Estimate: 12 hours.

Total Logic & Testing: 3 + 8 + 5 + 10 + 8 + 12 = 46 hours.

Total Effort Calculation and Time Estimate

Summing up all estimated hours:

Backend & Database: 39 hours
Frontend: 23 hours
Export/Import Logic & Testing: 46 hours

Grand Total Estimated Hours: 39 + 23 + 46 = 108 hours.

Assuming a standard 8-hour work day, this equates to approximately 108 / 8 = 13.5 working days.

Considering potential complexities, unforeseen issues, and buffer for code reviews and deployment, this rounds up to 2-3 weeks of focused development effort for a single developer or a small team.

Time Estimate: 2-3 weeks.

Derive Effort Score

A time estimate of 2-3 weeks falls into the 'Medium' complexity range on our scale.

It involves significant backend changes (new API endpoints, database schema).
It requires careful frontend implementation for UI/UX.
Crucially, it includes complex data handling logic for import/export and conflict resolution, which carries inherent risks and requires thorough testing.
This is more than a simple UI tweak or a minor backend fix.

Therefore, mapping 2-3 weeks of estimated work to the effort scale:

EFFORT SCORE = 5

Time Estimate

2-3 weeks

Decomposition of Feature Components

The 'Deck Sharing' feature can be broken down into several key technical components:

Backend/API:
- Generating unique shareable links/codes.
- Storing sharing permissions and associated deck IDs.
- API endpoints for creating, retrieving, and potentially revoking shares.
- Handling import logic: parsing shared data, merging/conflicting with existing decks.
- User authentication/authorization for sharing and importing.
Database:
- New tables to store shareable link data (e.g., share_id, deck_id, user_id, created_at, expires_at, access_level).
- Potentially modifying existing decks table to include sharing status.
Frontend:
- UI elements to trigger sharing (e.g., 'Share' button).
- Displaying the generated shareable link/code.
- UI for importing/accepting a shared deck (e.g., input field for code, confirmation dialog).
- Handling import success/failure feedback.
Export/Import Logic:
- Defining a standard format for deck data export (e.g., JSON).
- Implementing robust parsing and validation for imported data.
- Logic for merging or handling duplicate cards/decks upon import.

Impact

6/10

Revenue Proxy

Reduces churn by ~0.6% absolute among engaged users; Increases session frequency/duration by ~10% for 15% of MAU; Generates ~75 new users/month via viral sharing.

Identify Primary Business Metric Affected

The primary business metric impacted by the 'Deck Sharing' feature is User Engagement and Retention.

Engagement: Sharing decks encourages active use of the app beyond individual learning. Users might spend more time browsing shared content or curating decks to share.
Retention: By fostering a sense of community and collaboration, the feature can increase user stickiness. Users who share and collaborate are less likely to churn. It also acts as a potential viral growth loop, bringing new users into the app via shared links.

Estimate Problem Scope and User Need

Assessing the potential user base for this feature:

Target Audience: The app targets 'General mobile app users' likely including students, professionals, and lifelong learners. Many of these use cases benefit from collaborative learning.
User Feedback/Demand: While not explicitly stated, the rationale 'Many users want to be able to share their flashcard decks with friends, classmates, or other learners' suggests this is a known or anticipated user need. Let's assume ~15% of the active user base would find this highly valuable.
Active Users: Assuming a hypothetical app with 1,000,000 Monthly Active Users (MAU).
Potential Adopters: 1,000,000 MAU * 15% = 150,000 users who would actively use or benefit from this feature.
Frequency: Users might share/import decks perhaps once or twice a month initially, increasing with network effects.

Research Baseline Metrics and Industry Benchmarks

Benchmarking the potential impact:

User Retention: For apps with strong community or sharing features, retention can be significantly higher. Sharing features can improve 30-day retention by 5-15% relative for engaged users.
Engagement Metrics: Apps with sharing features often see increased session duration and frequency. A 10-20% increase in average session length for users who engage with sharing features is plausible.
Viral Coefficient (k-factor): If sharing leads to new user sign-ups, it can directly impact growth. A k-factor of 0.1 to 0.3 from sharing alone would be significant.
Monetization: For a freemium/ad-supported model, increased engagement (more sessions, longer duration) directly translates to more ad views or a higher likelihood of conversion to premium features.

Calculate Expected Improvement - Engagement Focus

Calculating the potential lift in engagement and retention:

Engaged User Base: We estimated 150,000 users would find this valuable.
Retention Improvement: If this feature reduces churn by 2% absolute among these engaged users, and assuming these users represent 30% of the total MAU churn pool, that's a 0.6% absolute reduction in overall churn.
Engagement Boost: For the 150,000 active users, let's assume a 10% increase in their average session frequency or duration due to sharing/collaboration activities.
Monetization Proxy: If average revenue per user (ARPU) is $0.50 per month, a 0.6% reduction in churn (out of 1M MAU) preserves 1M * 0.6% * $0.50 = $3,000 in monthly revenue. The increased engagement could potentially add another $1,500 - $3,000 per month through ads or premium upgrades.

Estimated Monthly Revenue Uplift: $4,500 - $6,000.

Calculate Expected Improvement - Viral Growth

Estimating the viral growth potential:

Share Rate: Assume 5% of the 150,000 highly engaged users share a deck per month. This means 7,500 shares initiated per month.
Conversion Rate: Assume 1% of shared links lead to a new user installing the app (a conservative estimate for a potentially niche feature).
New Users per Month: 7,500 shares * 1% conversion = 75 new users/month.
Annual Impact: 75 users/month * 12 months = 900 new users/year.

While 900 new users per year isn't massive on its own for a 1M MAU base, it represents a small but positive organic growth channel. If the average lifetime value (LTV) of a user is $10, this adds $9,000 in potential annual value.

Derive Impact Score

Synthesizing the expected impact:

Retention: A 0.6% absolute reduction in churn is a moderate improvement.
Engagement: A 10% uplift in session frequency/duration for a significant segment (15% of MAU) is also moderate.
Monetization: An estimated $4.5k-$6k monthly revenue uplift is moderate.
Growth: An added organic growth channel bringing ~900 users/year (worth ~$9k LTV) is minor to moderate.

This feature directly addresses a user need, fosters community, and has tangible, albeit not transformative, benefits across retention, engagement, and potentially growth. It sits comfortably in the middle ground of impact.

Considering the combined effects, it's more than a minor quality-of-life improvement but not a game-changer for revenue. It provides a solid, measurable benefit.

IMPACT SCORE = 6

Revenue Proxy

Reduces churn by ~0.6% absolute among engaged users; Increases session frequency/duration by ~10% for 15% of MAU; Generates ~75 new users/month via viral sharing.

Identify Primary Business Metric Affected

The primary business metric impacted by the 'Deck Sharing' feature is User Engagement and Retention.

Engagement: Sharing decks encourages active use of the app beyond individual learning. Users might spend more time browsing shared content or curating decks to share.
Retention: By fostering a sense of community and collaboration, the feature can increase user stickiness. Users who share and collaborate are less likely to churn. It also acts as a potential viral growth loop, bringing new users into the app via shared links.

Expected Profit

Financial modeling for revenue projection

Return on Investment

347%

Internal Rate of Return

24.8%

Net Present Value

$156K

Payback Period

17/mo

Related Reviews

EDIT: I still love this app - but the sharing feature isn't showing up anymore. Was it removed? I'd love to be able to help out my classmates with a few decks :) I never rate apps, this is my first time, but this is such an awesome free resource. I wanted to get on and say thank you. If you're trying to learn something new, this app will help!

Amber Mae·2/23/2021

Really good app! The only way it could be better it's if it implemented tags, if ou could export the deck to share it with pther users and if you could add pictures to the cards on pc

Selene·1/17/2021

It's a simple and fast app. 4 stars because it is a little too simple. The ability to share decks would be cool and an option to type responses would be awesome. Add audio and this would be a great replacement for TinyCards.

Alan Watchorn·6/18/2020

I really love this app! It's really well designed and looks pretty. It's very easy to add cards to and gives you lots of options to add images, formatting etc. It's also handy to have a web app where you can add cards, although I'd love to see a way to practise on the web as well. I'd love to see some swipe gestures for revision and a way to share decks with friends would also be really useful, but it's already helped me a lot!

A Google user·4/1/2020

So far I have fallen in love with this app. It has Space Retention, you can choose from a wide variety of beautiful images for your decks, and you can edit your decks also. it's also very simple to use. It's just too bad that I can't share my decks with friends, unless I am missing something about how to do that.

A Google user·2/7/2019