Somebody has made one of these to monitor PSI levels in a plastic bottle as an experiment, but the important thing is:
the PSI in the bottle is not going to peak when carbonation in the liquid it peaked. The PSI in the bottle increases as the headspace pressurizes with CO2 and then PSI _decreases_ as it's absorbed into the liquid.
With a sensitive enough gauge it'd possibly show you when the liquid has absorbed the CO2 based on the pressure having lowered and stabilized, but it would only be slightly more useful than the plastic bottle test and really would best be done using a plastic bottle anyways.
There's no simple way to have a turkey pop-up timer style indicator as there's no linear correlation of bottle pressure to liquid carbonation, especially since different carbonation temperatures will influence the absorption rate of the liquid over time, so the same batch carbonated at different temperatures would have completely different PSI levels in the bottles even if the final product is exactly the same but some just took longer.
Wild Love Brewing
Brew Stats | Brewlog | Fermentation chamber
Drinking: Late for Breakfast Stout, How Rye Am I? Saison, HD 2013, Graff
Bottle conditioning: Nut Brown Ale, EdWort's Hause Pale Ale
Primaries: Dry Irish Stoat, Oatish