Finnish mobile phone design is derived from the history of the 1984 Mobira Talkman and the 1989 Cityman.

Plenty of people in the mobile industry have started companies that operate in Finland, either national or foreign ownership basis.

One of these is the Bittium from Oulu: Manufacturer of security phones

Russian Yota Devices phone manufacturer design team is also in Oulu, Finland.
Marshall of the British London telephone was also designed in Oulu.

Huawei has a research center in Helsinki.

A group of former Nokia sorts founded Jolla: The company’s main product has been further developed Meegosta Sailfish operating system, but the company still released the phone and called Jolla Tablet Jolla.

Nokia’s heritage will also take forward fresh HMD Global, which acquired the rights to produce last week Nokia phones.

Salo phone manufacturing starting Turing Robotic Industries is not exactly a Finnish company. However, it set up a phone Finnish Sailfish OS and manufactures their equipment in Salo former Nokia factory.

Source: http://www.digitoday.fi/mobiili/2016/05/25/puhelinten-teko-ei-suomesta-lopu-tassa-ovat-nokian-perilliset/20165650/66?rss=6

Microsoft Writes Down $7.6B Of Its Nokia Acquisition, Announces 7,800 Layoffs | TechCrunch
http://www.epanorama.net/newepa/2015/07/09/microsoft-writes-down-7-6b-of-its-nokia-acquisition-announces-7800-layoffs-techcrunch/

Microsoft to buy Nokia’s phone business
http://www.epanorama.net/newepa/2013/09/03/microsoft-to-buy-nokias-phone-business/comment-page-6/#comment-1491821