Prefix Dialer Pro vs Duoboard
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Prefix Dialer Pro
Automatically add dial codes or modify phone numbers before making calls. Ideal for office PBX systems, international dialing, or any situation requiring number reformatting. Sync rules across devices via iCloud.
- Automatic prefix and replacer rules
- Contact integration
- Clipboard detection
- Manual number entry
- Dial history
- iCloud sync
- Shake to open contacts
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Prefix Dialer Pro lets you automatically prepend dial codes and transform phone numbers before placing a call — perfect for office PBX systems, international dialling, or any setup where numbers need a prefix. HOW IT WORKS Set up one or more prefix rules (e.g. "00" or "9") and replacer rules (e.g. strip the leading "+"). When you dial a number from your contacts, clipboard, or manually, every enabled rule is applied automatically. FEATURES • Contacts — pick any phone number directly from your contacts • Clipboard — detected automatically each time you open the app • Manual entry — type a number without opening your contacts • Dial history — quickly redial recent numbers • Shake to open contacts picker • iCloud sync — rules stay in sync across your devices • Up to 1 prefix and 1 replacer free; Go Pro for unlimited GO PRO A single one-time purchase unlocks unlimited prefixes and replacers and removes all ads. GREAT FOR • Staff who dial through a PBX (prepend 9 or 0 to get an outside line) • Frequent international callers (replace + with 00 or a country code) • Anyone whose phone system requires number reformatting before dialling
Duoboard
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Duoboard puts your keyboard on one half of the open iPhone Duo and a productivity sidekick on the other. Or split the keys across both. LIVE EDIT No more cursor dance. Everything you've typed shows up right beside the keys, word by word, big enough to hit. Tap any word to swap it, fix it or retype it, without wrestling with the text in your app. Pinch two words to join them, or spread one to split it. In Half and in Split. HALF The keys on the screen you're holding, and your sidekick on the other: Live Edit, emoji with search, a number pad and symbols, your snippets and your clipboard. SPLIT One keyboard, a half under each thumb, like on iPad. Spread two fingers on the keys to split them, pinch to bring them back together, and drag the halves wider or narrower to fit your hands. Choose which keys show on which side. DUAL A whole keyboard under each thumb, split across the fold. FULL Or keep it classic, one keyboard across the whole screen. ONE-HANDED, WITHOUT THE FUSS • Sweep two fingers or flick the space bar toward a thumb, and the keyboard drops into Half under it. Sweep again to tuck the keys in for one hand. No holding the globe key, no menu. • On the closed Duo, flick the space bar toward your thumb for one-handed keys, and back for full width. • Drag the keyboard to any height and set its width, remembered for closed, open upright and open sideways. TYPES THE WAY YOU DO • Swipe typing, with suggestions as you swipe • Autocorrect that learns your words and your contacts' names, and reads the words before it • Next-word suggestions after a space • Missed spaces come apart: "itsjust" becomes "it's just" • Hold the space bar for a trackpad: the higher your thumb, the faster the cursor • Hold 123 for snake_case, kebab-case, camelCase or file paths • An optional number row, and a touch and hold on a letter for its accents • Emoji search that forgives typos • What you just copied waits in the suggestion bar, one tap to paste • Undo and redo in the suggestion bar • Set how fast the delete key repeats SNIPPETS AND CLIPBOARD Save the things you type all the time, your address, your email, a go-to reply, and send them with a tap. Duoboard can also keep what you copy, so it's there when you need it again. ON IPAD TOO Duoboard works on iPad too, Split and Live Edit included. PRIVATE Nothing you type leaves your device. No account, no ads, no tracking. DUOBOARD PRO The Full keyboard is free, with autocorrect, emoji, snippets and your clipboard. Duoboard Pro unlocks Half, Split, Dual, Live Edit and swipe typing: try it free for 7 days, then keep it with a one-time purchase. No subscription.
Screenshots
Verdict
The clearest difference is update cadence: Duoboard at daily against Prefix Dialer Pro's every 8 months. Prefix Dialer Pro's advantage is iOS requirement (17.0 vs 26.0). On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Prefix Dialer Pro sells 2 one-off in-app purchases and Duoboard sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for Prefix Dialer Pro against 5.0 for Duoboard. Both are backed by a comparable volume of ratings — 1 and 2 respectively.
Prefix Dialer Pro ships an update every 8 months, Duoboard daily. Both last shipped on November 13, 2026.
| Parameter | Prefix Dialer Pro | Duoboard |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (2 ratings) |
| Number of ratings | 1 | 2 — better |
| Update frequency | Every 8 months | Daily — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | — |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 17.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 4 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | SOHO S & N | Patrick Gatewood |
Customer experience
Prefix Dialer Pro
Duoboard
In-app purchases
Prefix Dialer Pro
- Additional Set of 5 Prefixes and 5 Replacers$0.99
- Set of 5 prefixes and 5 replacers$0.99
Duoboard
- 7-Day TrialFree
- Duoboard Pro$1.99
Questions
Is Prefix Dialer Pro free?
Is Duoboard free?
Which has better reviews, Prefix Dialer Pro or Duoboard?
Do Prefix Dialer Pro or Duoboard have ads?
Which is updated more often, Prefix Dialer Pro or Duoboard?
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