Assuming you don’t want to spend $10/month for the Artscroll Daf Yomi subscription, you can always download “U’v’lecht’cha Baderech.” It has lots of seforim (including Shas) and, best of all, is 100% free.
I believe it’s “onyourway” written as one word. It has Rashi and Tosafos below the text of the gemarah. It does not have tzuras hadaf. It is a very nice app though.
italmud iPad edition is pretty amazing. If you dont have a 3g iPad then you need to download the Tezuras Hadaf and audio while on wifi but you can store a lot of daf and audio.
Also the Daf Hachaim.org website is brilliant and iPad compatible (but you need internet access)