Seeking Consultation on placing MS Access application "in the cloud".

I have a number of different clients that I sell an MS Access application to. Some are standalone single users and some are looking for maybe up to 6-7 users being able to access the Database both from the office and remotly. However my clients have very limited budgets. Solutions that can be implemented individually to my clients will need to be looked at as well as maybe a central soloution controled by me the cost of which I can include in my monthly support charge or initial product charge.
Your role will be to suggest and detail an efficient and cost effective solution.