Most Valuable Professional

View Jan Karel Pieterse's profile on LinkedIn subscribe to rss feed
Subscribe in a reader

Subscribe to our mailing list

* indicates required

File crashes Excel!!

Save my workbook!
The best tool for salvaging problematic workbooks.


Excel VBA Masterclass (English)
Excel VBA for Financials (Dutch)

Third party tools

Speed up your file

The best tool to optimise your Excel model!

Repair your file

Stellar Phoenix Excel Repair
Best tool to repair corrupt Excel sheets and objects

Your Excel Expert; uw Excel specialist

Welcome to the website of

JKP Application Development Services.

If you are looking for an Excel specialist and an Excel and VBA expert you've come to the right place.

My core business is developing solutions using Microsoft Excel/VBA and Access/VBA. Integration with other (Office) programs is possible.

Need expert Excel help? Get in touch.

My Services page lists some example projects.

Need Excel or VBA training? Information about our Excel and VBA trainings can be found on our trainings page.

If you need more information about me, look at my English homepage.

To find out whether you've actually found an Excel expert, I invite you to browse through my Excel articles.

I also recommend to try my free utilities.

Click here for remote assistanceClick for remote assistance

Welkom op de website van

JKP Application Development Services.

Als u op zoek bent naar een echte Excel specialist en een Excel en VBA expert dan bent u aan het juiste adres.

De nadruk ligt op het ontwikkelen van toepassingen in Microsoft Excel/VBA en Microsoft Access/VBA. Ook integratie met andere (Office) programma's is mogelijk.

Kunt u de hulp van een Excel expert gebruiken? Neem dan contact op.

Op de Diensten pagina vind u voorbeelden van projecten.

Zoekt u Excel of VBA cursussen? Informatie over onze Excel en VBA trainingen kunt u op onze training pagina vinden.

Wilt u meer over mij weten ga dan naar mijn Nederlandse homepage.

Wilt u zelf beoordelen of u een echte Excel expert heeft gevonden, bekijk dan mijn Excel artikelen.

Probeer ook eens mijn gratis hulpprogramma's.

Klik hier voor hulp op afstandKlik voor hulp of afstand


What's new on this site:

(English and/or Dutch content)

Nieuw op deze site

(Engelse en/of Nederlandse artikelen)

Access backup tool updated
I have updated my Access Backup utility so it now also orks on 64 bit Access.
Wed, 10 May 2017 08:15:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. Finally fixed an intermittent issue with the Visualize functionality on Excel 2016
Mon, 08 May 2017 16:20:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. Improved performance for Excel 2013 and 2016
Wed, 26 Apr 2017 14:20:00 GMT

Our Amsterdam Excel Summit was great
Our Amsterdam Excel Summit has been a great success. We had two very well received days full of Excel and Power BI sessions. Find links to photo impressions on my events page.
Tue, 25 Apr 2017 10:40:00 GMT

Update: Excel File Remediation Utility
Our Excel File Remediation Utility has just been updated. I have added an option to remove all styles from the workbooks. This is very useful if you have Excel files with corrupt styles.
Thu, 23 Mar 2017 15:40:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. Added jump to pivotsource when you trace precedents when in a pivottable.
Fri, 03 Mar 2017 13:00:00 GMT

Update: RefTreeAnalyser
RefTreeAnalyser 2.0 has just been updated. Fixed issue regarding range names in formulas.
Sun, 19 Feb 2017 13:20:00 GMT

Update to Flexfind
Updated: Flexfind. Added support for replacing in Powerquery M code (Excel 2016).
Sat, 18 Feb 2017 19:10:00 GMT