Cape Verde

I just visited Cape Verde this summer and I used a travel agency there, Vista Verde, that I can highly recommend.
Its website is as follows.
http://www.vista-verde.com/en/
The agency responded very quickly to my Internet inquiries and arranged an itinerary to three islands as per my requests that included accommodations, transport, sightseeing and walking with English-speaking guides and an internal inter-island flight. The agency also arranged for my visa in advance which speeded things up at the airport.

I used TAP to fly round-trip between Lisbon and Cape Verde.

As you know, visa requirements depend on nationality, purpose of visit and length of stay, and of course are subject to change. This past summer US citizens were able to get a visa on arrival for tourism purposes.
However, to make it easier and quicker at the airport, I asked the travel agency to apply in advance for me for an extra cost of 10 Euro. The agency then sent me a letter for the immigration official. The payment line was a bit long and chaotic, so it was faster with the letter.

Below is the excerpt from the travel agency's letter concerning the visa:

The price of a visa is 35 EUR for us to apply in advance, but you can also pay it on spot upon arrival. The visa on spot is 25 EUR.

If you wish us to apply, all you have to do is send me or my colleagues a copy of your passport.

Hope the above helps.

Just so you know, when I started researching going to Cape Verde, I discovered that it is a destination for package tours from the UK. If you are interested in doing such a tour, you might want to research that. Also, while visiting the islands I found out that there are many people from Cape Verde or their descendants living in the US, especially in Rhode Island and Massachusetts and, at least this summer, there was even a direct flight from Cape Verde to Providence, Rhode Island!