Apps I use: Whatsapp
Excellent:
Usability
UI
Good
Features (far better than sms but still plays catch up with Telegram)
End to End Encryption: messages are by default encrypted from they leave the senders phone until they arrive with the recipient.
Ugly:
Owned by a guy I have reasons not to trust, for now at least.
A little back story:
2 years ago Whatsapp was the best messaging platform I knew of.
It worked flawlessly, was beautiful and had a decent monetization strategy: USD 1/User/Year.
The only missing piece was an API. The only thing I didn’t like about them was their active hostility towards anyone who tried to make APIs and I could partly understand that as well.
Then they where bought up by Facebook and alarms went off immediately. While all hope was not lost, assuming that Facebook ownership would in any way improve on an app whose main selling points was privacy and strong focus on usability was kind of far fetched but all hope was not lost as we could hope they’d leave it alone.
However the next warning sign showed up quickly afterwards: Whatsapp would now be free and they would monetize it in another way, possibly by selling API access or something IIRC.
Later sweeping changes to privacy policies was introduced, taking effect by default unless the user actively opted out. These new policies would allow Facebook to link user data between Whatsapp and Facebook.
AFAIK they have been stopped from doing this in EU because of EU regulations, but for me I now consider Whatsapp unwanted and actively tell users to leave like I used to actvely recruit users for them.