The tombstone of Sikh martyr Bhai Maharaj Singh Ji, housed at the Silat Road Sikh Temple, holds special significance to the community.

The late Maharaj Singh is revered for his bravery and for planning a revolt with his followers against the British Raj in Punjab, India.

As punishment, the British sent him to Singapore, then a penal colony in 1850, and he was jailed at the now-defunct Outram Prison. He died here in 1856.

His unmarked tomb in the forested grounds where Singapore General Hospital is today was moved to the Silat Road Sikh Temple in 1966.

This story is documented in a free mobile app called Sikh Heritage Trail, which was founded and developed by Mr Ishvinder Singh, 29, a project engineer in an aerospace company.

The app, which cost $20,000 to build and was partially funded by the National Heritage Board, was officially launched yesterday.

Available both on the Android Google Play Store and the Apple App Store, it covers a trail of the Sepoy Lines area around Outram Road and Cantonment Road. This was where the sepoys, or Indian soldiers in the British Raj, built their barracks.

A trail through Bukit Brown Cemetery and its surrounding cemeteries, home to 30 pairs of Sikh guard statues, is also featured in the app.

Mr Singh and his team of two full-time app developers Chris Cai, 29, and Melody Ho, 24, as well as head researcher Vithya Subramaniam, 27, a South Asian studies graduate student at Columbia University, spent about three years putting together the app.

Their research involved site visits, conducting interviews with heads of Sikh temples here, and browsing materials from the National Archives of Singapore as well as overseas libraries.

Mr Singh said: "We didn't want to only talk about prominent Sikhs... we wanted also to share about the lives of everyday Sikh families, as well as their interactions with historic sites here."

The sites featured include the Upper Barracks and Lower Barracks on Pearl's Hill, which were built in 1934 for the Sikh Contingent of the Straits Settlement Police to live in.

Mr Singh, who hopes the app will reach at least 10,000 people, said he will be updating it with more information about the Sikh community over time.

"As Sikhs, we have very strong visual identities with the turbans we wear and the facial hair we keep. I wanted to explore how we fit into modern Singapore and better understand the Sikh heritage and share the findings with a larger audience."