The app should be ready by autumn 2017, with versions for both iOS and Android devices.
"People no longer just be warned by sirens and radio," the call for tenders explains, according to 20 Minuten. "In the future, the spread of local information should be done via a push notification for all phases of an event."
The government also intends to use the app more frequently than radio alerts or sirens are currently used, in order to keep the public better informed.
The Federal Office for Civil Protection (FOCP) first announced its plans to build an app in late July, reportedly inspired by the swift response of German police to the Munich shooting. Then, local police used social media networks to communicate with the public and issue instructions as well as timely updates on the situation.
Now a call for tenders has been issued - a necessity under World Trade Organization (WTO) guidelines, as projects exceeding 230,000 francs must be open for competition. The final cost of the project is not yet known and will depend on the offers received.
The system will use an existing app as its basis; Alertswiss 1.0, which was created by company Zurich Ubique Engineering, in 2015. Alertswiss issues information about attacks or disasters and advice on what to do in order to stay safe and minimize damage, for example during floods.
This app cost 148,304 francs to build and has been downloaded 38,000 times, but the government hopes the new version will be even more widely used.
The idea is similar to a national alert system launched in France ahead of the Euro 2016 championships, following the co-ordinated attacks across Paris in November last year.
However, makers of the French app came under fire in July, when the app took hours to update following the truck attack in Nice on Bastille Day which left 86 dead and hundreds more injured. The SAIP app did not alert users until around 90 minutes after the event.
And even in this early stage, the Swiss plan has also attracted criticism.
A telecoms expert at Verivox, Ralf Beyeler, criticized the "reliance on technology which would overload the mobile networks in case of crisis," Le Matin reported.
Beyeler favoured the use of a Cell Broadcast system instead, a system less liable to crash under heavy traffic and which is used as part of Japan's earthquake warning system.