it is also worth mentioning the ClearCash icount - this provider although cannot help repair credit rating, can help you manage your finances better - they have a budgeting tool which is really useful and tracks your spending.
one thing to look out for with the credit builder through cashplus is if you miss a payment, you could end up far worse than when you started!
If you are going to use it, use it properly to help - both providers have great tools to help you get back on the financial stability ladder