I could not find a Guitar Tuner that worked for me, so I wrote Fat Tuna. FT is an easy to use chromatic guitar tuner. It includes these (my favorite) tunings:
Open D Minor
DADGAD (D Modal)
Open G Minor
Half Step Down
One Step Down
Open A (2 versions)
Open E (2 versions)
Open E6 (2 versions)
Open A Minor (2 versions)
Tap the tuning button and you'll see the tuning panel.
The app shows the expected frequency for each string in your selected tuning. When you pick a note on your guitar, the screen indicates the note picked and the frequency of the note.
You match the actual frequency number to the expected number to get perfect pitch. For me, +/- 10 cents is fine.
Please let me know in your review or through the support website, if you need other tunings. I will add them.
At the bottom of the screen is an amplitude meter that can help you determine ambient noise level when trying to tune.
Serious bug fix..
With Family Sharing set up, up to six family members can use this app.