Never tried from the mobile app before.It's okay, you just need more experience working the poll.
Counterspell is pretty infrequently used in my games as I have a player pool which means the frequency with which a wizard might be at a given session is low.
Not every day features a fight against a spellcaster. Maybe 1/3 days.
On those days, Counterspell is used about twice per round for the duration of the encounter. Sometimes more, sometimes less.