I have been researching nearly all reasonable CRM's out there to implement for my full time job... that research had put me in touch with what is now my partner in a new venture to fork our own CRM. We have a cloud based CRM, but it doesn't exactly fit your need, it's a bit heavy.
It's very lightweight, has geographical distribution, a simple to understand and intuitive setup.
Their mobile apps is the best for what you're seeking. Nothing I have tried comes close to how light it is.
When I first tried it it was $15/user/month. Now it's $20, and worth every penny.
Take a trial run at their website you'll be impressed. They have a service model much needed in today's cloud - it's easy to get someone on the phone, chat, or email reply.
They're simply a pleasure.
Even though we have created our own CRM I plan to use Nutshell until we need our own heavier solution, and of course sign up as a reseller for their CRM for our clients that it fits well, like you and me. :)
Best of luck!
- David Monk Sr.