When it comes to booking airfares, everyone wants an upgrade, but they’re not always available.

Even when they are, you may not always have the mileage status on that airline to qualify for the front of the plane.

But now there are 40 airlines and a few apps offering the opportunity to bid for that seat upgrade.

Singapore Airlines, for example, is now offering economy class passengers the chance to move up one class.

The airline sends passengers an email seven days before their scheduled departure.

Then they get to bid. Minimum and maximum bidding amounts will be displayed.

If the bid wins, they’re notified within 48 hours before departure.

There’s now an app for the upgrade bidding as well.

It’s called SeatBoost, and it auctions off unsold premium class seats.

A leader board can even be checked.

If a passenger is bested, he/she can bid again.

If a passenger pays double the airfare only to bump up to premium economy, it just might not be worth it.

For more information about travel apps you can use on the road, check out:

• A New Tool that Can Help You Get Around Europe
• Travel Apps You Can Use to Track Flights & Find WiFi
• Get the Most Out of Your Road Trip With These Travel Apps

Keep reading for more travel tips.