What (features) makes an app effective/ worthy enough to be downloaded?

Question

There are millions and millions of apps out there on Google play store and the other stores. Only a few become popular and will be widely used and downloaded. As users of many apps, which factors do you think makes an app effective or worthy to downloaded?

Examples...
- simplicity, end-to-end encryption ->WhatsApp
- User friendly, community, updates -> SoloLearn
-Privacy, security, photo sharing ->Instagram...

Post your answers, even the smallest features matters....

Answer 1

Relevance.
- I really don't need another five apps to tell me what time it is.

Functionality.
- This includes everything which has been, and will be listed out in this thread. Responsiveness, user-friendliness, performance, smoothness, reliability, low power consumption, features, etc. It all comes down to the same thing.

Innovation.
- There are tons of apps with good UI/UX. For an app to stand out from the rest requires a differentiating factor, something new, beneficial.

Answer 2

- User friendly, even for beginners.
- Doesn't require too much data, or high speed transfer.
- Good users community
- Performance, it's nice if app can run on low-end devices
- Offline features

Answer 3

offline support

I don't touch any software without it

Answer 4

responsive - design's adorability -handy ...

Answer 5

1.User friendly to every user.
2.Tight security and privacy.
3.High quality data format.
4.Can run on any device.
5.Best communication features.
6.Smooth on every device.
7.Best futureistc interface.