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Telecom & Security Mobile App
CallShield — A community-built spam-call blocker

Instantly see who's behind any unknown number — spam calls auto-blocked by the community.

TelecomGuard Co., Ltd. — Builds a phone-number database from user reviews, identifies the caller on incoming calls, and auto-blocks spam numbers. A participatory app where review posts earn points redeemable for coupons.

3M+
Identified number DB
Community posts
Instant
Identify caller on incoming call
Native OS call screen
Reward
Points for reviews
Redeem coupons
Challenge
Before

Users cannot tell whether to answer unknown numbers and keep receiving spam and sales calls. Looking up numbers every time is a hassle, and reporting brings no personal reward, so cooperation fizzles out.

  • Want to decide whether to answer unknown numbers
    Anxious not knowing the caller
  • Don't want spam or sales calls
    Can't block them all alone
  • Want to instantly identify a number
    Searching online every time is tedious
  • Want a reward for reporting and blocking
    No motivation to keep helping
Solution
After

User reviews are aggregated into a community DB and synced to each device. iOS uses a CallKit extension; Android uses device integration to identify the caller on incoming calls and auto-block spam numbers. Contributors earn points redeemable for coupons — a self-reinforcing feedback loop.

UsersReceive call CommunityRate number CallShield Platform Rating aggregation Identification DB Device sync (CallKit) Points management Block control Caller IDShow on call Spam blockerAuto-reject Points rewardRedeem coupons Everyone's reviews bring safety to all
callshield.example.jp
Incoming 050-1234-5678 ⚠ Likely spam call Community ratings 842 posts Spam Sales Useful Block Rate Points balance 1,240 pt
Caller ID & review screen
Tech Stack Swift (CallKit) Kotlin MVVM · Room Retrofit/OkHttp Koin DI
6months
24man-months
Want it for your company? → info@amela.vn