If I can’t guess a reading that works, I would use handwriting pad or handwriting IME. With knowledge of radicals / Kanji parts. Remember stroke orders for each radicals (not Kanji) could be a requirement.
OCR like Samsung AI Select (or Smart Select) might work, but I don’t find it very accurate enough…
I also use a dictionary app for Android, Aedict. In the past, I used Akebi and Takoboto for Android, and Japanese 
for iPhone.
Yomitan can be installed on Firefox for Android, but it can’t search on typing. Jisho website also doesn’t search on typing before pressing Enter.
I don’t know about Jisho app version, but it seems not to be officially made from Jisho website people. I don’t know about additional features anyway.
I don’t use this one myself, but the website looks helpful. KanKan: kanji-component-aware online Japanese dictionary
In short, get a phone app. Also, considering installing a Japanese IME on a touchscreen device (rather than just from an app or a website).