The latest version MCleaner v1.5.0 supports iPhone 2.0. Updating is totally free to our customers. To those who have purchased version 1.4, you can use the register code to activate the new version.

More info you can see :

How to install MCleaner v1.5.0 on iPhoneOS 2.0:
1) Jailbroken iPhone (3G iPhone)
2) Launch Cydia, and Choose the Utilities Category
3) Choose MCleaner and Install