Be The Best — E-Learning Platform

Be The Best is a comprehensive e-learning app built at Elkood, giving students an interactive study toolkit plus a social layer of real-time Q&A and instructor chat. Both App Store and Google Play links are live.

Core features

• Study toolkit — subjects, notes, flashcards, timed practice questions, and a study planner with reminders and streaks.
• Video lessons — hardware-decoded playback with per-lesson resume and screenshot prevention (iOS AVPlayerLayer; Android FLAG_SECURE via platform channel).
• Encrypted offline PDFs — study materials stored encrypted with a per-user key derived from the auth token; resumable downloads; key deletion on logout renders files unreadable.
• Real-time Q&A and chat (SignalR) — reconnection with missed-message recovery (fetch-since-last-ID), typing indicators, and delivered/seen receipts.
• Subscriptions — StoreKit / Play Billing with server-side receipt validation and a domain-modeled subscription state machine.

Technical highlights

• Missed messages after reconnect — on reconnect, fetch messages since the last received ID before resuming the live stream, merging with deduplication so users never see a gap.
• Subscription staleness — a short-TTL local cache plus a server status check on launch and on any premium-content access, since status can change outside the app.
• Queued JWT refresh — concurrent 401s share one refresh attempt, preventing the duplicate-refresh race.

Result

A feature-dense production app where the invisible real-time work — reconnection, offline queues, receipt validation — is what makes the visible features trustworthy.