Nanologue is described as 'boasts a wide scope of inspiring sounds and professional sound effects, sporting a straightforward multi-touch interface and a great-sounding monophonic synthesizer' and is an app in the Audio & Music category. There are more than 10 alternatives to Nanologue for a variety of platforms, including iPad, iPhone, Mac, Windows and Linux. The best alternative is Surge Synthesizer, which is both free and Open Source. Other great apps like Nanologue are AudioKit FM Player (Paid, Open Source), Auxy Music Studio (Freemium), Modular Synthesizer (Paid) and Addictive Synth (Paid).
Jasuto allows you to visually construct your own synths/effects, and use them to make sequences all on your device! With the addition of a fully-featured sampler you can now record/resample/edit, and even create entirely new samples by drawing right in the app.
Groovebox is a beautifully designed mobile music studio packed with inspiring synths and drum machines. In minutes you’ll be making beats and melodies, playing world-class instruments, and creating great new music.