Datawind was among four finalists in a competition organised by UK Trade and Investment.
The firm hopes the Ubislate, which sells for Â£22 ($35), will make digital connectivity more affordable.
The three other finalists in the Smart UK Project were Blippar, P2i and QRpedia.
Seventy-nine UK-based companies entered the competition in December.
A key factor in selecting the finalists was that they demonstrated the potential to become global businesses.
The winner of the competition was announced at the Mobile World Congress in Barcelona.
As well as the prestige of winning, Datawind will get free design consultancy and free software.
Russell Buckley, one of the Smart UK Project judges, said: "We were very impressed by the quality of all the finalists.
"It was a tough decision but we are very pleased that Datawind has won.
"There is a global potential and the will to transform lives and society, all using the resources of a British company."
Suneet Singh Tuli, chief executive of Datawind, said the result was a "great validation of our vision".

Norfolk and Suffolk Foundation Trust said funding offered by central Norfolk clinical commissioning groups (CCG) does not meet the "volume of demand".
A trust board meeting was told the CCGs were "not commissioning sufficient capacity" in beds or staffing levels.
The central Norfolk CCGs said they were still in negotiations.
At the meeting Andrew Hopkins, director of finance, said funding arrangements had been agreed with all its CCGs apart from central Norfolk.
The meeting heard the plans put forward by central Norfolk CCGs did not provide enough funds for out of area placements, when no beds can be found in the area.
There were also issues surrounding staffing levels.
In previous years, the trust has been criticised over the need to send patients outside of Norfolk and Suffolk due to a shortage of mental health beds.
The BBC revealed that in November last year the cost of sending Norfolk and Suffolk mental patients to other parts of the country almost tripled to Â£600,000, from an average of Â£200,000 a month in December 2013 to September 2014.
In December, the trust said the number outside the counties had been cut to 24 from a high of 50 earlier in the year.
Non-executive director John Brierley said: "The issue is the commissioners are not commissioning sufficient capacity to the volume of demand."
If no agreement is made the dispute will go to arbitration where a final decision is made by NHS England and health watchdog Monitor.
Trust chief executive Michael Scott said after the meeting: "We don't think there is adequate funding for mental health. It remains the Cinderella service.
"In some areas such as Suffolk and Great Yarmouth and Waveney we have managed to agree funding.
"Unfortunately across central Norfolk we are unable to agree and we have to go to arbitration."
A Norfolk CCGs spokesman said: "CCGs across Norwich, South Norfolk and North Norfolk are still in discussions with the trust regarding the 15/16 contracting year.
"All parties are hopeful of a swift conclusion to current negotiations."
In February, this year the trust became the first of its kind in England to be put in special measures due to it not providing a "safe service".
The makers of a 7in (17.8cm) Android tablet have been named "UK's Most Innovative Mobile Company".
[NEXT_CONCEPT]
Cash for future mental health provision in Norfolk and Suffolk has "fallen short" of what is needed, prompting a dispute with an NHS trust and a funder.