I started using Anki daily around 3 weeks ago. I made myself a 'general' deck for inputting whatever random things I want to have in my memory. I've put in some simple mathematical definitions and productivity stuff like Czikzsentmihalyi's list of identifying features for flow. I'm planning on trying to read Penrose's The Road to Reality, Lawvere's Conceptual Mathematics and Gelman's Bayesian Data Analysis and making cards of the memorizable stuff like formulas and definitions and see how that goes.

The phone is no good for writing new cards, so you'll want the deck on a PC as well, and then you'll be wanting an easy way to synchronize between the two. An ankiweb account does this very nicely. Of course you can just manually pass the .anki deck file between the phone and the PC as well.

I've also picked up premade decks for the Lojban language gismu root words (gismu by frequency), the pubilic Heisig Kanji deck and a hiragana/katakana deck. I've set these to add 10 new words/symbols per day. Textbook stuff is hard to understand by just grabbing some other person's deck, but basic foreign language vocabulary is much more context-free, so it's easy to do with the premade decks. (It's a good idea to have read through Heisig's mnemonic guide for the kanji before drilling them though.) After a week of drilling the hiragana, I can now recognize most of the alphabet without aid. AnkiDroid also has a whiteboard function which lets you draw the kanji/kana before showing the answer, which is quite handy.

Doing the vocabulary stuff feels quite effortless now, more like playing a casual game than doing work. The SRS takes care of boring stuff like figuring out what needs reviewing and keeping track of the materials, and I just need to come up with weird mnemonics for stuff.

Anki has support for embedded Latex, and doing mathy stuff will probably involve using it sooner or later. You need a PC with Latex installed to generate bitmap files for the cards from the formula markup. The phone can't do this, so you'll need to transfer the PC-generated formula images over.

Anki on PC supports having your media in a Dropbox account. Dropbox support is apparently forthcoming for AnkiDroid. In the meanwhile, you'll want an Android program that downloads entire Dropbox folders, like dropboxdownloader and manually download the png directory from your Dropbox account.

The generated formulas are also likely to have too large a DPI for an Android device. I got the Configure latex plugin for Anki from Anki's Download plugin menu command, and edited the DPI value in file plugins/Configure latex.py to 100 from 150. (The settings line looks like latex.latexDviPngCmd = ["dvipng", "-D", "100", "-T", "tight"] after editing.)