Here are the award‑search / award‑availability services frequent flyers most often use, with a short note on what each does and why people pick it. (All descriptions are based on current public info — I’ve cited each service below so you can check specifics.)

• ExpertFlyer — longtime go‑to for seat and upgrade alerts, flight/seat maps, and award-class searches; best if you want fine‑grained alerts (paid tiers). Note: ExpertFlyer’s coverage of some carriers’ award classes has changed in recent years, so double‑check if a particular airline is supported. (expertflyer.com)

• Point.me — broad multi‑program award search that matches routes to transfer partners and shows booking instructions; user‑friendly for people with transferable points (paid). Good for beginners who want one place to compare programs. (point.me)

• Roame — fast, calendar/region “SkyView” searches plus route alerts and transfer recommendations; strong for flexible travelers who want quick, wide searches and alerts. (thepointsparty.com)

• Seats.aero — modern award search engine with “Explore” maps, live searches for pro users, and unlimited alerts on some plans; praised for speed and seat‑class detail. Good alternative to ExpertFlyer for many programs. (seats.aero.)

• SeatSpy — focused reward‑seat finder (strong for Avios/British Airways and similar programs) with calendar views and alerts; popular in the UK/Europe market. (seatspy.com)

• PointsYeah — fast multi‑day award searches, good filters and free tier; popular for quick searches across several programs and for hotel award searches too. (nerdwallet.com)

• AwardFares (AwardFares / AwardFares.com) — multi‑program award search + alerts and timeline/calendar views; positions itself as a real‑time alternative to older cached tools. (awardfares.com)

• AwardTool — powerful “mega” searching (many simultaneous queries), aimed at power users who want large window or many‑route scans; good for heavy searchers. (frequentmiler.com)

• Points Path (PointsPath) — browser extension that overlays award pricing onto Google Flights (shows which programs can book a cash result and roughly how many miles); convenient for folks who already use Google Flights. (pointspath.com)

• AwardWallet — not an award search engine but the most‑used tool for tracking miles/points balances and posting alerts (Balance Watch). Frequent flyers use it alongside search tools to know when points post. (awardwallet.com)

• JuicyMiles — search + paid concierge/booking service (also offers search tools); useful if you want a paid team to assemble and book complex award itineraries. (insideflyer.com)

Quick tips and caveats

• No single tool covers every airline or every kind of award inventory; some display partner‑bookable “saver” seats only, others show airline‑member‑only inventory. Always verify availability directly with the airline/program before transferring points. (wsj.com)
• Many services use cached data or scraping; alerts and live searches reduce risk of “phantom” availability but don’t eliminate it — act quickly when you get an alert. (wsj.com)
• If you want one recommendation by use case: ExpertFlyer or Seats.aero for seat/upgrade alerts and detailed inventory; Point.me or Roame for broad multi‑program searches and transfer guidance; SeatSpy for BA/Avios‑heavy searches; AwardWallet to track balances. (expertflyer.com)

If you want, I can:

• check whether any of these services cover a specific airline or route you care about; or
• compare pricing/features for 2–3 tools you’re considering.