Some more travelling аппаратчикs I installed on my iPhone before setting off:
Metro Minsk (iTuneslink): Not the most sophisticated tube app, but it should do the job for a day. Also contains some POIs, restaurants and a map.
Moscow: Metropolitan (iTuneslink) and Moscow Metro (iTuneslink) are two apps I tried out to navigate the Russian capital.
Beijing: Beijing Metro (iTuneslink)
Currencies (iTuneslink) tells you how much your hotel room, bus ticket, souvenir, blini or beer is. Make sure to update exchange rates once in a while (done automatically when the app is started, but you're not always connected to wifi, are you?). Easy to use, good interface:
Mandarin phrasebook (iTuneslink): When I traveled China about 8 years ago the LP Mandarin phrasebook came in very handy, in particular when it comes to buying train tickets etc. It was also very well organized in sections and had some background information on all topics. Unfortunately I can't say the same about its electronic cousin. While it has the big advantage that you can quickly access the relevant topics and can actually play the matching mandarin voice, it lacks much of the background information the book comes with and seems to be less complete. Well, as long as it helps you finding the right party and a female doctor, I guess it does the job...
some food apps: On my first time in China I met some volunteers working for an NGO who gave me a "generic menu for Chinese restaurants". Basically a list of typical dishes written in Chinese with the corresponding English translation. The waiter had always great fun indicating what they could serve up from the list, called their colleagues and we all had a laugh until my gong bao jiding arrived. Now there are some apps that do the same, some better, some worse. I'll see how it works. I have not found one yet, that lets you take a picture of the Chinese writing on the menu and looks up the dish. That would be something, wouldn't it? Check these here out: China Menu (iTuneslink) easy to navigate lots of pics, cnMenu read (iTuneslink) reads the dishes in Chinese for you, but no pics, Chinese Food Menu (iTuneslink) good selection, but requires data connection.
some other useful аппаратчикs:
shazam (iTuneslink) works surprisingly well to identify music that is being played if there is not too much background noise. So if you plan to take the soundtrack home, play the song to the app and have it analyzed. Needs a data connection, so watch your roaming costs.