Comparison

Locky vs pKaTool

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Locky

Personalize your iPhone's lock screen with stunning depth effect wallpapers and customizable clock styles. Automatically update your background daily or hourly to keep your device looking fresh and unique. Easy to use for all iOS users.

Highlights
  • Depth effect wallpapers
  • Customizable clock styles
  • Personal message addition
  • Automatic wallpaper changes
  • Live wallpapers added weekly
  • Dynamic themes
Features
Read full description

Introducing the ultimate customization app for iOS 17 - Locky! This app lets you take control of your iPhone's lock screen and make it truly your own. With Locky, you can choose from a wide variety of stunning depth effect wallpapers that will make your lock screen come alive. These high-quality wallpapers are specially designed for iOS 17, and they'll make your iPhone look and feel like a brand new device. But that's not all - our app also lets you customize your lock screen in other ways. You can choose the clock style, change the font color, and even add your own personal message to the screen. And if you want to keep things fresh, you can set your lock screen to automatically change every day or every hour. Locky is incredibly easy to use, with a user-friendly interface that makes customization a breeze. Whether you're an iOS expert or a first-time user, you'll love how simple it is to create a lock screen that reflects your personality and style. So if you're ready to take your iPhone to the next level, download Locky today and start customizing! We add new live wallpapers and dynamic themes weekly to give your iPhone a fresh look. Stay tuned! SUBSCRIPTION TERMS *The price is for US customers. Pricing in other countries may vary and actual charges may be converted to your local currency depending on the country of residence. *Payment will be charged to iTunes Account at confirmation of purchase. *Subscription will be automatically renewed for the same price and duration period, auto-renew can be turned off at least 24 hours before the end of the current period. *Your account will be charged for the subscription fee within 24 hours prior to the end of the current period for the price initially selected. *Subscriptions may be managed by you and auto-renewal may be turned off by going to the user's iTunes Account Settings. *Unused portion of a free trial period will be forfeited when a user decides to subscribe. Privacy Policy: bit.ly/Locky_PrivacyPpolicy Terms of Use: bit.ly/Locky_TermsOfUse

About

pKaTool

Features
Read full description

pKaTool — Titratable Groups, Made Intuitive pKaTool is a hands-on lab for exploring how acids and bases behave when they're not alone. Real proteins pack titratable groups close together in active sites, and their pKa values shift because of it — coupling that's easy to state on paper but hard to feel until you can play with it. Built for the classroom as much as the lab bench. Set up a system of titratable groups, assign each an intrinsic pKa and an acid or base identity, then adjust the pairwise interaction energy between them. pKaTool solves the exact Boltzmann partition function for every protonation state — no approximation, no Monte Carlo sampling — and redraws the titration curve live as you move the sliders. NEW: pH-activity profiles Mark which protonation state of an active site is catalytically competent, and pKaTool overlays the resulting pH-activity profile on the chart — the same calculation behind published pH-dependent enzyme activity curves. Watch how coupling between two or three residues can shift an enzyme's pH optimum by a full pH unit. NEW: Six systems from the literature Load real, published active-site electrostatics instead of only synthetic examples — intrinsic pKa values and interaction energies transcribed directly from an NMR/GloFTE study of enzyme active sites (Sondergaard et al., J. Mol. Biol. 2008), including a wild-type xylanase and its N35D mutant reproducing a published pH-activity optimum shift (5.7 to 4.6), ribonuclease A, and both oxidation states of thioredoxin. Initial version based on Analysing the pH-dependent properties of proteins using pKa calculations, Jens Erik Nielsen J Mol Graph Model. 2007 Jan;25(5):691-9. doi: 10.1016/j.jmgm.2006.05.007. https://pubmed.ncbi.nlm.nih.gov/16815056/ What you can explore: • Intrinsic pKa vs. effective pKa — watch a group's apparent pKa shift as neighboring charges turn on and off • Repulsive vs. attractive coupling, applied automatically from each group's acid/base identity, just like real electrostatics • Back-titration — the counterintuitive case where a group re-protonates partway through a titration because its neighbors' charge state changes the energetics • pH-activity profiles for enzyme active sites, and net charge and isoelectric point across your full pH range Why it's useful for teaching: • See, in real time, why two nearby acidic or basic residues almost never titrate independently — the classic Henderson-Hasselbalch curve is the special case, not the rule • Build intuition for back-titration, charge inversion, and buffering plateaus by dragging sliders instead of reading about them • Reproduce a real published figure from the primary literature, not a toy example Built for exploration: • One live screen — sliders, interaction matrix, and titration curve all update together, no "calculate" button • Save and switch between named systems to compare setups, including the six built-in literature examples • Adjustable pH scan range and resolution • No account required — systems stay on your device • Occasional non-personalized ads support development; Remove Ads turns them off Whether you're teaching enzyme active-site behavior, building intuition before a kinetics experiment, or just curious why a catalytic residue's pKa never matches the textbook value, pKaTool lets you turn the knobs yourself and watch the physics respond. Original code license: # pKaTool - analysis of systems of titratable groups # Copyright (C) 2010 Jens Erik Nielsen # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details.

Screenshots

Locky4 screens
pKaTool4 screens

Verdict

The call

The clearest difference is in-app purchases: pKaTool at none against Locky's 6. pKaTool also leads on update cadence (every 4 weeks vs every 2 months). Locky's advantage is iOS requirement (14.0 vs 16.0). On price, ads and device support 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Locky sells 6 in-app purchases, starting at $1.99 per 7 days. pKaTool asks for nothing beyond the download.

UpkeepUpdate frequency

Locky ships an update every 2 months, pKaTool every 4 weeks. The most recent releases landed on November 7, 2026 and October 31, 2026 respectively.

Scorecard3 real differences · 7 level
Locky versus pKaTool: the parameters behind the verdict, then further details
ParameterLockypKaTool
PriceFreeFree
Rating4.5 (504 ratings) — better—
Positive reviews54.5% of reviews—
Number of ratings504 — better—
Update frequencyEvery 2 monthsEvery 4 weeks — better
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPodiPhone, iPad
Requires iOS14.0 — better16.0
Further details — not scored
Size112 MB4 MB
Age rating4+4+
DeveloperRAMAN LAPATKOJENS ERIK NIELSEN

In-app purchases

6 purchases

Locky

Subscriptions6
  • Premium Access$1.997 Days
  • Premium Access3 Days trial$1.997 Days
  • Premium Access$5.991 Month
Show 3 more
  • Premium Access3 Days trial$5.991 Month
  • Premium Access$18.991 Year
  • Premium Access3 Days trial$18.991 Year
None

pKaTool

No in-app purchases

Questions

Is Locky free?
Locky is free to download, with in-app purchases available.
Is pKaTool free?
pKaTool is free to download, with no in-app purchases.
Do Locky or pKaTool have ads?
Both Locky and pKaTool show ads.
Which is updated more often, Locky or pKaTool?
Locky ships an update every 2 months, and pKaTool every 4 weeks. Most recently, Locky was updated on November 7, 2026 and pKaTool on October 31, 2026.

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