Co vs ERSB Lite
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Co
This app provides advanced word prediction and spelling support for students. It offers grammar-smart suggestions and access to millions of topic-specific dictionaries to aid in writing. Built-in text-to-speech functionality helps users review their work.
- Grammar-smart word prediction
- Millions of topic-specific dictionaries
- Flexspell™ technology for spelling errors
- Built-in text-to-speech
- Personalized vocabulary and settings
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Co:Writer® Universal app and third-party keyboard gives students easy access to word prediction on iPad, iPad Pro, iPhone, and iPod Touch. Students simply sign in to their Co:Writer Universal accounts to write with their personal settings and vocabulary. ABOUT CO:WRITER UNIVERSAL This version is for schools with a Co:Writer Universal license only. Users without a Co:Writer Universal license must purchase the Co:Writer app. HOW DOES CO:WRITER WORK? As letters are typed, Co:Writer predicts the intended word with a selection of word suggestions using powerful grammar-smart word prediction. These suggestions can be read aloud with a swipe. Selecting the intended word places it into the writing document. For feedback while writing (and after writing) built-in text to speech can be used to read letters, words, sentences, and the entire document. 4+ MILLION TOPIC-SPECIFIC DICTIONARIES Co:Writer has access to a main prediction dictionary (that includes core words) and Topic Dictionaries (that includes topic specific words). Co:Writer can access over 4 million topic-specific dictionaries which are activated based on the writing task. A small sampling of the variety of topic dictionaries: - America's Cup - Apple II - Compare and Contrast - Dinosaurs - Grumpy Cat - History of the Peloponnesian War - Mahatma Gandhi - My Dog - Pig Latin - Rolls-Royce Silver Ghost - SpongeBob SquarePants - Tommy (album) - Wonders of the World SPELLING SUPPORT Co:Writer handles the widest range of spelling mistakes through its Flexspell™technology including phonetic spelling and inventive spelling errors (letter omissions, word ending omissions, letter reversals, etc). Examples of how Co:Writer aides with phonetic and/or inventive spelling: Before Co:Writer The blk jargon flu over the bra lfnt. R u hpy to ce me? I no hw to nor the fone. After Co:Writer The black dragon flew over the gray elephant. Are you happy to see me? I know how to answer the phone. GRAMMAR SUPPORT Co:Writer bases its prediction off of proper grammar, and uses its understanding of grammar to accurately predict words within the framework of valid sentence structures. Examples of how Co:Writer aides with grammar: Dogs are furry. (noun, verb, adj.) - When you typed d-o, you get plural noun choices Three very mangy dogs ran down the street. (adj., adv., adj., noun, verb… etc.) - After typing three, very, mangy, you get plural noun choices, then you get plural verb tenses. OTHER FEATURES - Built-in Text to Speech - Export
ERSB Lite
This app builds early reading skills for students progressing from foundational literacy. It uses systematic instruction and assessments to help individuals read independently, proving effective for those with intellectual disabilities and autism.
- Early literacy skill development
- Systematic instruction
- Ongoing assessments
- Progress to 2nd-grade reading level
- Effective for intellectual disabilities
- Effective for autism
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Note: This is the Free version of ERSB. Level 1 with 5 lessons is Free! The rest of the levels are available through the in-app store. Early Reading Skills Builder™(ERSB) curriculum, based on a multi-year research project from the University of North Carolina at Charlotte, is a stepping stone for graduates of Attainment’s ELSB Curriculum. ERSB takes students who mastered these early literacy skills to a 2nd grade reading level. It incorporates systematic instruction and ongoing assessments to teach students to read independently. It’s been proven effective for students with moderate to severe intellectual disability and/or autism, including those with complex communication needs.
Screenshots
Verdict
The clearest difference is rating: ERSB Lite at 4.0 against Co's 2.6. ERSB Lite also leads on update cadence (every 2 months vs every 4 months). Co's advantage is in-app purchases (none vs 5) and ratings volume (17 vs 3). On price 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. ERSB Lite sells 5 one-off in-app purchases. Co asks for nothing beyond the download.
ERSB Lite holds the better App Store score, 4.0 against 2.6. That said, the two scores are not equally well evidenced: Co has 17 ratings behind it against 3, so its average is the more settled of the two. Written reviews complicate that: 8% of Co's written reviews are positive against 0% of ERSB Lite's, so the app with the better star average is not the one people write more warmly about.
Co ships an update every 4 months, ERSB Lite every 2 months. The most recent releases landed on October 29, 2026 and November 1, 2026 respectively.
| Parameter | Co | ERSB Lite |
|---|---|---|
| Price | Free | Free |
| Rating | 2.6 (17 ratings) | 4.0 (3 ratings) — better |
| Positive reviews | 8.3% of reviews — better | 0.0% of reviews |
| Number of ratings | 17 — better | 3 |
| Update frequency | Every 4 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPad |
| Requires iOS | 10.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 45 MB | 253 MB |
| Age rating | 4+ | 4+ |
| Developer | Don Johnston Incorporated | Attainment Company |
Customer experience
Co
ERSB Lite
In-app purchases
Co
No in-app purchases
ERSB Lite
- Levels 12-16$29.99
- Levels 17-21$29.99
- Levels 22-26$29.99
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- Levels 2-6$29.99
- Levels 7-11$29.99









