In April, the start-up was forced to put off its planned IPO when Google threatened to remove its apps from the Play Store, with the alleged reason being that Unlockd did not conform to Google's policies.
The Australian firm then obtained court injunctions from the British High Court and the Australian Federal Court, preventing Google from disabling AdMob-generated advertising content and removing Unlockd apps for the company's UK business from the Google Play Store.
But on Tuesday, the company apparently decided that it could not carry on in this fashion.
"As such, we have not been able to secure the capital we had expected to replace the IPO and therefore have been left no choice but to move into voluntary administration."
The two companies first got into conflict earlier this year, when Google claimed that the start-up was violating its terms of service, even though clear explanations had been provided on how its apps could be made compliant with Play Store rules.
Unlockd's business model is built around consumers agreeing to view content on their mobile screens when they unlock their phones. In exchange, users get rewarded in different ways, such as getting discounts on their monthly mobile bills.
Its apps run only on the Android operating system meaning that the threat by Google, if carried through, would more or less cut off its blood supply.
Unlockd returns about 70% of the ad revenue it gets to its users, while Google, which dominates the mobile ad market, does not offer a cent back.
In its statement, Unlockd said: "We believe that Google’s conduct and the effect of its actions represents a further example by them of anti-competitive conduct toward innovative start-ups such as Unlockd, that might pose a future threat to their position in the market.
"Until wide-reaching change is brought about to prevent companies like Google from abusing their dominant market positions, consumers and innovation will continue to suffer."
The Australian Competition and Consumer Commission is currently conducting an inquiry into digital platforms and the Unlockd case may make it to the organisation's radar.
Contacted for comment, a Google spokesperson referred iTWire to a statement issued on 17 April, which read: “Our publicly available AdMob and Google Play policies clearly set out how our products may be used, and are designed to protect the interests of advertisers, publishers and phone users.
"We explained our concerns to Unlockd, outlined how they could fix the problems or use alternatives, and gave them time to make changes. And despite having agreed at the outset to comply with our product policies, their app remains in infringement today."