This app was mentioned in 10 comments, with an average of 1.10 upvotes
I have a physical Kanii dictionary that I never use. It has something like three ways to look up, and it works, but it's slower than an app.
Mostly, I use an app called Kanji Recognizer. You can draw the kanji, view options, and then select the kanji that you think us the match. https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer
I use Anki for Android with a Hesig's Remembering the Kanji deck and use the Kanji Recognizer app to test myself.
Most programs recognize the existence of Kanji Recognizer, so they just integrate with that quite often (or rather, KR integrates with them):
https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer
I use this one: Kanji Recogniser
It's very fickle about stroke order, though. Sometimes I have to use my dictionary app and search by radicals.
I have used Kanji recognizer but it is not that great as the one integrated with the "Xperia japanese keyboard" that comes with my phone which has an awesome drawn kanji recognizer. That being said, it did help me figure out kanjis at a time when I needed.
https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer Kanji Recognizer, by Nikolay Elenkov, has helped me a lot :D
i use this one. https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer
you do need to know how stroke order works for it to pick it up reliably, though
https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer
I don't know how it compares to others.
Besides Obenkyo, I found Kanji Recognizer to have a pretty reliable detection engine when quizzing.
手書き入力ってものがあるよ。
https://play.google.com/store/apps/details?id=org.nick.kanjirecognizer
こういうもの使ってみるといいんじゃないかな?