Costa Rica

There are 3 network providers on the air in Costa Rica: Since 2012 first MVNOs have started. The most successful of them called Tuyo Móvil is featured. Others like Fullmóvil don't offer good data packages up to now.
 * I.C.E., with its prepaid product called kölbi (state owned)
 * Movistar (Spanish owned by Telefónica)
 * Claro (Mexican owned by América Móvil)

Nowadays, it's very easy to buy a prepaid SIM card for a foreigner. You only need to show your photo ID or passport. Since end of 2014, all SIM cards need to be registered with Sutel, the national regulator, not only the operator. When they don't register your prepaid SIM in store, go online to Sutel registration website (in Spanish only), register your SIM card and wait for some hours to be activated. If you want to maintain your SIM card for more than a year, Sutel will send you an email and you may need to reconfirm your registration after one year. Otherwise, your card may be blocked.

kölbi (by I.C.E.)
The I.C.E. for Instituto Costarricense de Electricidad, the state-run electricity and telco service provider, has still the best coverage nationwide. So this is the best choice, if you travel within the country especially outside the Central Valley. Their prepaid product is called kölbi. 2G (to EDGE) on 1800 MHz, wide coverage, 3G (to HSDPA) in the populated areas on 850 MHz ICE 3G/4G Coverage Map 4G/LTE has been rolled out this year as the first provider on 2600 MHz (band 7) mostly in the Central Valley.

Availablity
They have a store at the San José airport (4:30h-22h) which is convenient for arriving passengers and the employees mostly speak English: ICE National Stores List

Their prepaid SIM card is called chip and costs about 1,000 Colones depending on promotions. The "Súper Chip" comes with a credit of 1,000 Colones and when you make a recharge of 500 Colones or more in the first 7 days, you get 150 MB internet for 3 days included. These offers are on 3G and 4G/LTE where available.

Recharges can be made by vouchers called cards (tarjetas) of 500, 1000, 2500, 5000, 10000 Colones or US$ 10 or 20, or electronically from 100 to 25,000 Colones at many agencies throughout the country.

Data feature packages
The default rate for internet is 0.00858 Colones per KB at speeds up to 2 Mbps on 3G and 6 Mbps on 4G. They offer 5 data packages: To subscribe, simply text code to 8888. Every plan renews automatically, if there is enough credit. To unsubscribe text 'salir internet' to 8888. Overuse is charged with the default rate.

Data-only SIM
Kölbi has special prepaid rates for for tablets, MiFis and modems called "Planes kölbi Datos Prepago": Activation is by texting code to 8888. All plans auto-renew. Deactivation by texting 'salir internet' to 8888.

Technical Settings

 * APN: kolbi3g

Movistar
Movistar is good in the Central Valley, but can be patchy elsewhere. 2G on 1800 MHz, 3G (to HSDPA) on 850 and 2100 MHz and 4G/LTE has started in San José on 1800 MHz and spread major towns in the provinces so far with a 70% coverage: Movistar Coverage Map

Availability
The SIM costs 1,000 or 2,500 Colones in their own stores Shop Locator and a lot of sales outlets. To activate a SIM with a foreign passport, text 'ACTIVAR  Your Name  Your Passport No.' to 1693, or call 1693 during regular business hours and select option 9 when prompted. 

Data feature packages
They offer the following packages on 2G, 3G (up to 2 Mbps) and 4G/LTE where available: Default rate is 0.0086 Colones per KB.

To subscribe: Enter the keyword to 606 or use USSD code *123#. The packages Diario and Nocturna auto-renew, the others don't. To unsubscribe text 'DIARIOBAJA' or 'NOCTURNOBAJA' to 606. Overuse is charged by the default rate.

For unthrottled speeds they offer these new combo packages called Paquetes 4G prepago: To subscribe: Enter the name of package to 606 or use USSD code +123#. To check data balance text 'CUPO' to 606.
 * Diario 4G: 24 hours, 250 MB, 25 Movistar mins, 25 domestic SMS: 800 Colones
 * Semana 4G: 7 days, 1 GB, 200 Movistar mins, 200 domestic SMS: 4,000 Colones
 * Mes 4G: 30 days, 3 GB, 2000 Movistar mins, 2000 domestic SMS: 11,000 Colones

Central America roaming option
In 2015 Movistar started its "sin fronteras" (without borders) option for regional roaming in Central America. By activating *123#, you can surf on the Movistar networks of Mexico, Guatemala, El Salvador and Panama for the domestic Costa Rican rate.

Technical Settings

 * APN: internet.movistar.cr

Claro
Claro is the latest arrival. It has good coverage in the Central Valley, but can be quite patchy elsewhere. 2G is on 1800 MHz, 3G (to HSDPA) on 2100 MHz in the centers only. 4G has started on 2600 MHz in the Central Valley mostly: Claro Coverage Map. In 2015 4G/LTE has been opened for prepaid.

Availability
Claro charges you 1,000 to 2,500 Colones for the SIM they call chip. It is available in their stores Store Locator and other outlets. If you top up 1,000 Colones or more when you activate the card, they'll give you 300 MB data.

Data feature Packages
Default rate is 0.0086 Colones per KB. They have the following data bundles for their voice plans available: For activation text name of package to 444. All packages will automatically renew if there is enough credit. To deactivate text FIN to 444. Overuse is charged at the default rate.
 * DIA: 24 hours, 175 MB: 300 Colones
 * DIA FULL: 24 hours, 350 MB: 500 Colones
 * SEMANA FULL: 7 days, 400 MB: 2,300 Colones
 * MES FULL: 30 days, 2 GB: 10,000 Colones

Two social app packages for Facebook and Whatsapp are offered. 24 hours of Facebook or Whatsapp use up to 100 MB (excluding VoIP calls) at 350 Colones. Activation: Text 'FB' pr 'WA' to 444. Packages auto-renew.

Data-only SIM
Claro offers a data-only SIM for tablets and dongles. This can be loaded with these packages giving you seemingly unlimited data at a max. speed of 2 Mbps: For activation text the Spanish name for the package to 555. These packages don't renew for a change.
 * 1 día: 24 hours, 750 Colones
 * 7 días: 7 days: 4,900 Colones
 * 15 días: 15 days: 9,000 Colones
 * 30 días: 30 days: 17,500 Colones

Technical Settings

 * APN: internet.ideasclaro

Tuyo móvil
Tuyo móvil is one of the first MVNOs in the country and has the most users so far. It's a joint venture between the biggest TV station called Teletica and ICE. That's why it uses the network of ICE in 2G and 3G (see coverage above).

Availability
Their SIM card is sold for 1000 Colones with the same credit preloaded in lot of supermarkets like Walmart and other phone shops. Top-up cards recargas you will find in even more shops ranging from 500 to 10,000 Colones. To check your balance, text 'Saldo' to 7703.

Data feature packages
For data, they offer these packages with a max. speed of 2 Mbps on 3G: For activation, text code to 7702 or call 1700 and choose option 3. Packages won't auto-renew and you can buy a package ahead of time when the old one is used up.
 * 1 hour, 30 MB: 85 Colones, activation: Hora
 * 1 day, 150 MB: 420 Colones, activation: Día
 * 1 week, 750 MB: 2,100 Colones, activation: Semana
 * 2 weeks, 1 GB: 3,000 Colones, activation: Quincena
 * 1 month, 2 GB: 6,000 Colones, activation: Mes

Technical Settings

 * APN: tm7datos